From: Joakim Tjernlund Date: Tue, 13 Oct 2009 08:12:03 +0000 (+0200) Subject: i2c-mpc: Do not generate STOP after read. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=45da790ebe746bb29f7e4adf806c020db6ff7755;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git i2c-mpc: Do not generate STOP after read. The driver always ends a read with a STOP condition which breaks subsequent I2C reads/writes in the same transaction as these expect to do a repeated START(ReSTART). This will also help I2C multimaster as the bus will not be released after the first read, but when the whole transaction ends. Signed-off-by: Joakim Tjernlund Signed-off-by: Ben Dooks --- diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index d325e86e3103..f627001108b8 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -365,9 +365,6 @@ static int mpc_write(struct mpc_i2c *i2c, int target, unsigned timeout = i2c->adap.timeout; u32 flags = restart ? CCR_RSTA : 0; - /* Start with MEN */ - if (!restart) - writeccr(i2c, CCR_MEN); /* Start as master */ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags); /* Write target byte */ @@ -396,9 +393,6 @@ static int mpc_read(struct mpc_i2c *i2c, int target, int i, result; u32 flags = restart ? CCR_RSTA : 0; - /* Start with MEN */ - if (!restart) - writeccr(i2c, CCR_MEN); /* Switch to read - restart */ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags); /* Write target address byte - this time with the read flag set */ @@ -425,9 +419,9 @@ static int mpc_read(struct mpc_i2c *i2c, int target, /* Generate txack on next to last byte */ if (i == length - 2) writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK); - /* Generate stop on last byte */ + /* Do not generate stop on last byte */ if (i == length - 1) - writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_TXAK); + writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX); data[i] = readb(i2c->base + MPC_I2C_DR); }